Highly Selective Adsorption of New Bis-Opened-Triazine Materials Hybridized with a Cross-Linked Polymer Support for Palladium and Some Typical Coexisting Metals

A novel polymer hybrid bis-opened-triazine adsorbent, BOTZX, was prepared by impregnation and immobilization. It was achieved through the in situ introduction of a new monopyridine-derived bis-opened-triazine ligand, BOTZ, into the pores of the cross-linked inert polymer carrier under vacuum hybridization. The adsorption of 20 representative metals on BOTZX was studied over the ranges of 0.4 to 6.0 M HNO3 and 298 to 318 K. BOTZX had strong uptake ability and high selectivity for Pd over others except for Zr. The removal efficiency was more than 99.8% for Pd and less than 0.11% for others, except for Zr at 31.5%. The Pd adsorption capacity was 0.228 mmol/g under the optimal conditions of 1.0 M HNO3 and a contact time of 30 min at 298 K. The experimental data fit the Langmuir model well, reflecting the monolayer uptake mechanism. Thermodynamic parameters Delta H degrees, Delta G degrees, and Delta S degrees and valuable chemical engineering data of Pd adsorption were obtained. It is promising to apply BOTZX in the simultaneous removal of Pd and minor actinide from highly active liquid waste in the framework of the SPMP process.